Pilot study of minimally adherent silver dressings for acute surgical wounds

Abstract Background and Aims Minimally adherent silver dressings (SILVER MASD) are antimicrobial, nonirritating, provide a moist wound healing environment, and low cost. The purpose of this pilot, single‐center, non‐blinded randomized controlled trial was to quantify the outcomes of acute surgical wounds treated with MASD versus standard of care (SoC) dressings. Methods Thirty‐two patients with acute wounds were randomized 1:1 to be treated with MASD once weekly or SoC following surgical excision of skin and/or subcutaneous tissue between September 13, 2016 and November 28, 2017. The outcome variables included clinical infection, time to wound closure, and pain scores at dressing changes. Two independent, one‐sided sample t‐tests were performed to assess statistical significance. Results There was no difference in wound healing between SILVER MASD and SoC. Dressing changes were less painful for wounds managed with MASD silver dressings. Conclusions The results of this study suggest that MASD are not less effective in wound healing compared to SoC while also providing the benefit of decreased pain at dressing changes. Therefore, minimally adherent silver dressings can and should be considered a viable option in the management of acute surgical wounds.

change only an absorbent secondary dressing layer, leaving the silicone dressing in place. It is low cost, at $0.25 per square cm, or about $19.00 for the smallest size dressing, requires no durable medical equipment, and can be left unchanged for up to 14 consecutive days. 3 A pilot, single-center, non-blinded randomized controlled trial (RCT) found that patients whose skin-graft donor sites were dressed with silicone dressings demonstrated the fastest healing time and least duration of pain when compared to traditional moist-to-dry dressings. 4 With the growing recognition that more than 80% of bacterial infections are associated with biofilms, 5 antimicrobial and anti-biofilm activity is now included in the definition of the ideal wound dressing. 6 In modern wound dressings, several antimicrobial substances are used including iodine, honey, and ionic silver. Ionic silver has a broad spectrum of antimicrobial activity, most of which is facilitated by silver ions' ability to react with bacteria membrane proteins and DNA, disrupting DNA replication and denaturing proteins. 7 Moreover, ionic silver confers additional wound-healing benefits including antiplatelet activity, antioxidant effects, immunity enhancement, wound healing and bone regeneration, and an increase in antibiotic efficiency. 8 Bioactive silver also damages bacterial cell walls and dismantles pathogens' electron transport system, and it perforates cytoplasmic membranes, which induces metabolite loss and cell death. 7 Silicone minimally adherent dressings (Mepitel ® AG) are approved for sale in the United States. 9 The purpose of this study is to establish the outcomes of acute surgical wounds treated with MASD compared to standard of care (SoC) dressings through a pilot, prospective RCT.

| MATERIALS AND METHODS
An IRB-approved, pilot, prospective RCT was performed on patients undergoing surgical excision of skin and/or subcutaneous tissue between September 13, 2016 and November 28, 2017. Informed consent was obtained from all subjects. Subjects were randomized 1:1 to have sites dressed with either silver MASD changed weekly, or SoC.
Patients receiving silver MASD used ABD pads (Medline) as secondary dressings; the ABD pads were secured with paper tape and changed daily or more frequently as needed for saturation.

| RESULTS
Thirty-two patients were enrolled in the trial and randomized 1:1 to silver MASD versus SoC. Six subjects withdrew without undergoing any surgical procedures and one patient did not complete their follow-up visits. Of the 25 patients who had acute wounds, demographics (Table 1)   The average length of follow-up was 5.7 weeks (SD, 3.8). Ten patients were randomized to SoC ( Figure 1) and 15 were randomized to silver MASD ( Figure 2). There was no statistical difference in the average initial wound size (SoC 161.2 cm 2 vs. silver MASD 136.9 cm 2 , p = 0.71). With regard to the primary endpoints of this study (Table 2), there was no significant difference in infection rates, with 1 infection (10.0% or 1/10) in the SoC arm and 1 (6.7% or 1/15) in the silver MASD arm. There was no significant difference in time to wound closure (SoC 6.0 vs. silver MASD 4.4 weeks, p = 0.15).
Notably, wounds treated with silver MASD were significantly less painful (SoC 2.8 pain score vs. MASD 1.1, p = 0.008). Our data suggest that silver MASD is a reasonable option for management of acute surgical wounds due to its non-occlusive, minimally adherent nature, and its innate soft, pliable properties.
These characteristics make silver MASD appropriate for surgical wounds. Silver ions reduce the microbial load in the dressing and may contribute to healing without bacterial colonization. [11][12][13] The silver MASD's design and structure allow for wound exudate to pass through the dressing and retain a desirable level of wound moisture.
Conformability enables this dressing to be effectively used in wounds located in anatomically difficult areas such as the groin, axilla, and perineum. These qualities can also contribute to a longer wear time. A limitation of this study was that attaining a pain score at each dressing change for the deep wound in SoC group was not feasible.
For this reason, we also assessed differences in pain scores between the two groups with superficial wounds. This showed that average

CONFLICT OF INTEREST
The authors declare no conflict of interest.

DATA AVAILABILITY STATEMENT
The authors confirm that the data supporting the findings of this study are available within the article.